#!/bin/bash
# -*- sh -*-
#
# Plugin to monitor network connections.
#
# Parameters:
#
# 	config   (required)
# 	autoconf (optional - only used by munin-config)
#
# Bugs:
#       At least one SuSE netstat appears to report
#         "passive connections rejected because of time stamp"
#        We have never seen that, patch requested.
#
# Magic markers (optional - used by munin-config and some installation
# scripts):
#%# family=auto
#%# capabilities=autoconf

. $MUNIN_LIBDIR/plugins/plugin.sh

if [ "$1" = "autoconf" ]; then
	if ( netstat -s 2>/dev/null >/dev/null ); then
		echo yes
		exit 0
	else
		if [ $? -eq 127 ]
		then
			echo "no (netstat program not found)"
			exit 1
		else
			echo no
			exit 1
		fi
	fi
fi

if [ "$1" = "config" ]; then

	echo 'graph_title Netstat'
	echo 'graph_args --base 1000 --logarithmic'
	echo 'graph_vlabel active connections'
	echo 'graph_category network'
	echo 'graph_period second'
	echo 'graph_info This graph shows the TCP activity of all the network interfaces combined.'
	echo 'active.label active'
	echo 'active.type DERIVE'
	echo 'active.max 50000'
	echo 'active.min 0'
	echo 'active.info The number of active TCP openings per second.'
	print_warning active
	print_critical active
	echo 'passive.label passive'
	echo 'passive.type DERIVE'
	echo 'passive.max 50000'
	echo 'passive.min 0'
	echo 'passive.info The number of passive TCP openings per second.'
	print_warning passive
	print_critical passive
	echo 'failed.label failed'
	echo 'failed.type DERIVE'
	echo 'failed.max 50000'
	echo 'failed.min 0'
	echo 'failed.info The number of failed TCP connection attempts per second.'
	print_warning failed
	print_critical failed
	echo 'resets.label resets'
	echo 'resets.type DERIVE'
	echo 'resets.max 50000'
	echo 'resets.min 0'
	echo 'resets.info The number of TCP connection resets.'
	print_warning resets
	print_critical resets
	echo 'established.label established'
	echo 'established.type GAUGE'
	echo 'established.max 50000'
	echo 'established.info The number of currently open connections.'
	print_warning established
	print_critical established
	exit 0
fi

netstat -s | awk '
/active connections/      { print "active.value " $1 }
/passive connection ope/  { print "passive.value " $1 }
/failed connection/       { print "failed.value " $1 }
/connection resets/       { print "resets.value " $1 }
/connections established/ { print "established.value " $1 }'

